Discontinuous grain growth in the sintering of copper-ferrous ferrites

Abstract

Copper-ferrous ferrites were sintered under various conditions to elucidate the mechanism of discontinuous grain growth.Straight grain boundaries were observed in the discontinuously growing grains. This boundary was determined to be the (111) plane of growing grain. Dynamical consideration of the straight boundaries suggested the existence of a liquid phase. The existence of the liquid phase, which produces the straight boundaries and gives a large mobility to them, is considered to be the main cause of discontinuous grain growth.A possible new mechanism was proposed for the nucleation in the discontinuous grain growth. Final size of a giant grain produced by discontinuous grain growth was controlled by the initial grain size, firing temperature and oxygen content of samples.